I find it more likely that the harm done to your goal is not caused by public announcement of that goal, but rather announcing it is evidence that you aren't as committed to the goal as you are to other goals that you're better at sticking to. In other words, if you're having trouble with achieving something in particular, or working towards it, then you are likely to acknowledge that to yourself in the form of "needing to set a goal" and thus "announcing it to the world", thus automatically ensuring that announced goals are less likely to be kept by the very nature of the fact that they needed to be announced in the first place. If you want something badly enough, you are more likely to "just do it", thus foregoing the need to announce it to others.
Comments
I find it more likely that the harm done to your goal is not caused by public announcement of that goal, but rather announcing it is evidence that you aren't as committed to the goal as you are to other goals that you're better at sticking to. In other words, if you're having trouble with achieving something in particular, or working towards it, then you are likely to acknowledge that to yourself in the form of "needing to set a goal" and thus "announcing it to the world", thus automatically ensuring that announced goals are less likely to be kept by the very nature of the fact that they needed to be announced in the first place. If you want something badly enough, you are more likely to "just do it", thus foregoing the need to announce it to others.